Interlocking device for train-order signals.



No. 868,289. g PATENTED OCT. 15; 1907.

E. B. OVERHOLT. INT-BRLOOKING DEVICE FOR TRAIN ORDER SIGNALS.

APPLIOA'IIOH FILED SEPT. 20, 1901,

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No. 868,289. PATENTED OCT. 15; 1907'. E. E. OVERHOLT.

INTERLOGKING DEVICE FOR TRAIN ORDER SIGNALS.

APPLIUATION FILED 8EPT.20, 1901.

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PATENTED OCT. 15, 1907,

E. E. OVERHOLT. I INTERLOGKING DEVICE FOR TRAIN ORDER SIGNALS.

APPLICATION FILED SEPT. 20;}901.

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UNITED STATES EDWIN E. OVERHOLT, OF WASHINGTON, DISTRICT OF COLUMBIA.

INTERLOCKING DEVICE FOR TRAIN-ORDER SIGNALS.

Specification of Letters Patent.

Patented Oct. 15, 1907.

Application filed September 20, 1901. Serial No. 76,000.

To all whom it may concern:

Be it known that I, EDWIN E. OvERHoL'r, a citizen of the United States,residing at Washington in the District of Columbia, have inventedcertain new and useful Improvements in Interlocking Devices forTrain-Order Signals; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to devices for the safe operation of train ordersignals; and especially to that class of devices in which the signal islocked at danger, whenever the operator has undelivered train orders onhand.

The construction herein set forth is supplementary to that set forth inmy patent for safety device for display of train order signals, No.683,861, patented Oct. 1, 1901. V

The object of my present invention is to provide means adapting theinvention just referred to, to the requirements of the service on doubletrack roads; and also to provide means simple, reliable, and safe, forpermitting the operator to give a clear signal to a train for which hehas no orders while he has orders on hand for another train not yetarrived.

Other objects will appear in the subjoined description.

In referring to signals controlling trains running in oppositedirections I will, in order to render such reference more simple andtangible, refer to all such trains as running east and west; the termseast and west being used with the broad signification of denoting anygiven direction and its opposite.

It is apparent that on double-track roads, two signals-one for eastbound and the other for west bound trains might be successfullycontrolled by having two cabinets-one for each signal. But this wouldrender the cost of installation on these roads, about double thatrequired for single-track roads. Furthermore, in most instances, it isdesirable that the trainorder blanks for east bound and west boundtrains should be exactly alike in size and shape. This being the casethere would always be the possibility of getting the tablets mixed inrestoring them to their normal places in the cabinets: i. e. there wouldbe danger of getting the tablets for east bound orders, into the cabinetcontrolling the west bound signal, and vice versa. The evil that mightresult from such a mistake is apparent. Hence in the presentapplication, I have provided a single cabinet with means for controllingtwo signals; the upper part of the cabinet containing talfets for trainsrunning in onedirection, and the lower part containing those for trainsrunning in the opposite direction. With this arrangement there wouldstill be the danger of getting the tablets mixed, but for the specialmeans which I provide which renders it impossible to put the tablets foreast bound orders, into the compartment of the cabinet intended for westbound orders, or to put the tablets for west bound orders into thecompartment intended for east bound orders. Furthermore, on some roadsthey have what may be termed double orders, that is; a single order fortwo trains running towards each 'otherthe order to be delivered at theirmeeting point. Now the first thing that would suggest itself in a caselike this, would be to take two copies of the order, one on an eastbound tablet, and the other on a west bound tablet. Hence, unlessspecial provision were made to meet such a case, it would be necessaryto remove two tabletsone from the east bound compartment of the cabinetand one from the west boundin order to lock both signals at danger. Thiswould require double work upon the part of the operator; but what is offar greater consequence, there would also be the possibility of hismaking a mistake in copying the order onto the sec-- ond tablet. Someroads consider the danger of making a mistake in copying so great thatwhen it becomes absolutely necessary to take a copy of an order theoperator is required to trace it from the original. In view of thesefacts I have deemed it desirable, in addition to the separatecompartments for east bound and west bound orders, to also provide onecompartment for these double orders, having the tablet, normally housedtherein, so related to the mechanism with which it cooperates, that whenthis tablet is removed from the cabinet, both signals are locked atdanger. This tablet is usually of a different size and shape from theother tablets, so that it is a comparatively easy matter to providemeans for preventing it from getting replaced in the wrong compartment,after it has been withdrawn from the cabinet along with tablets from theother compartments. However in order to meet the most difficultcondition that could possibly arise, I have supposed in the presentinstance that it is of the same size and shape as the other tablets; andhave provided means such that it cannot be entered in the compartmentsfor either the east or the west bound tablets; nor can they be enteredin its compartment; and if through mistake the operator should attemptto enter any one of the three kinds of tablets in the wrong compartmentof the cabinet, the inevitable result would be that the device would notoperate and the signals would both be locked at danger. We thereforehave here a single cabinet controlling both signals, and carrying threekinds of train order tabletseast bound tablets, west bound tablets, anddouble tabletswith the con struction of the operative parts of thecabinet such that if an east bound tablet be withdrawn, the signalcontrolling east bound trains will be locked at danger; and if a westbound tablet be withdrawn, the signal controlling west bound trains willbe locked at danger; and if the tablet for double orders be withdrawn,both signals will be simultaneously locked at danger: further means alsobeing provided which compel that each kindof tablet be entered in itsown proper compartment whenever the tablets are put in the cabinet, sothat there can be no mixing or confusion there.

To insure safety in the movement of trains, the cabinet is soconstructed that whenever an operator desires a tablet upon which toreceive an order, he is compelled to set both signals at danger, andwhen he withdraws a tablet to receive an order for a train running in agiven direction, the signal controlling trains running in that directionwill be locked at danger, the tablet virtually acting as a key. Theother signal will also be secured against casual or accidentaldisplacement, by one of two downward projections of the sliding door,which projections take, one into each operating bar as the door islowered to open the cabinet. If however it should be desired to clearthe signal for which there are no orders the operator has only toelevate the door, which leaves the bar of the unlocked signal free to bemoved at will inasmuch as it was only engaged by the door. The otherbar, however will still remain locked, by the means broadly statedabove, which means will be more fully referred to hereafter.

As a means of extreme precaution, some R. R. oflicials prefer to haveeach individual tablet control two locks-a lock for each signalas doesour double order tablet in the present instance. Thus by the removal ofa tablet from the cabinet the operator locks both signals at danger, andis consequently sure to get the right one. This method also relieves hismind of the necessity of any discrimination, as to which tablet he shallwithdraw from the cabinet, when he is called to receive a train order.

My invention as set forth in my former patent compels that the act ofunlocking the cabinet sets the signal at danger, the act of opening thedoor locks the signal in that position, while the act of withdrawing oneor more tablets from the cabinet, still further locks the signal, toremain locked till all the tablets are restored to their normal positionin the cabinet, and the door closed upon them. It however frequentlyoccurs after orders have been received for a train; and the signalconsequently locked against trains moving in that direction, that beforethat order has been delivered, another train moving in the samedirection, and for which there are no orders, approaches the station,and the operator has no means of unlocking the signal to let it byexcept by replacing the tablet, containing the order, in the cabinet.This would be a risky thing to do, for reasons most apparent andconsequently, in the present application, I have shown means independentof the tablets for unlocking the tablet locks when it is desired topermit a train to pass without returning the tablet to the cabinet.

The means of accomplishing all these results will now be definitelypointed out, in the following specification, and illustrated in theaccompanying drawings, which form a part of. this application, referencebeing made to the different parts by means of numerals; the

same numerals referring to the same parts throughout the various figuresof the drawings in which,

Figure l. is a perspective view of my invention complete. Fig. 2. is aperspective with certain parts removed. Fig. 3. is a perspective view ofthe door. Fig. 4. is a perspective view of the tablet locks shown intheir operative relation to each other. Fig. 5. is a view of the trainorder tablets, designed to cooperate with the inner three of the righthand group of tablet locks; supposed in the present instance to controlthe east bound signal. Fig. 6. is a view of the tablet designed tocooperate with the inner three of the left hand group of tablet locks,supposed to control the West bound signal. Fig. 7. is a view of the formof tablet, designed to operate the outer member of each group of tabletlocks, and through them to control both signals. Fig. 8. is aperspective view of the tablet locks in their operative relation to eachother, with one of the east bound tablets entered in its normalposition, and operating one of said locks: a fragment of the box beingalso shown, to illustrate the position of the tablet, with relation tothe front edge of the shelves, when entered in its proper place. Fig. 9.is a view of the tablet locks similar to that shown in Fig. 8, andillustrates the result of attempting to enter a tablet in the wrongcompartment of the cabinet: a fragment of the cabinet being again shownto illustrate the relation of the front edge of the shelves to a tabletthus entered. Fig. 10. is a perspective showing the tablet for doubleorders in its normal position in the cabinet; also the stop used toprevent the other tablets from being entered in this compartment. Fig.11. is a vertical section of the cabinet with the door removed: thesection being taken sufficiently near one side of the cabinet to leavethe tablet locks undisturbed. Fig. 12. illustrates mechanism that may beused to unlock the cabinet and give a clear signal, while there areundelivered train orders on hand. Fig. 13. illustrates means foraccomplishing the same result without the use of a key.

The cabinet 1 made of any suitable material is provided with the shelves2 and the intervening spaces 3; the width of the shelves and spacesbeing equal. The sides 4 of the cabinet project slightly in front of theshelves, and these projections are each provided on the inner sidethereof, with a groove 5, adapted to easily receive the door 6 of thecabinet. This door is provided with a series of transverse cut-away anduncut-away portions corresponding in number and in width to the shelvesand intervening spaces of the cabinet, and designed to registertherewith.

The cabinet is designed to receive and house a series of tablets,supported by the shelves; and in order that these tablets may be moreeasily grasped, the central front portion of the shelves is cut away.For the same reason the central portion of the door is also cut away,the opening thus formed coinciding with the recess formed by the cuttingaway of the shelves.

The cabinet near the bottom thereof, carries the two horizontallydisposed operating bars 7 and 8, slightly separated from each other, toprevent any friction or binding of one against the other; and isprovided in its front and rear sides with apertures 9 designed toreceive said bars, which have free longitudinal movement therein.

The bars are provided with the handles 7 and 8 and at their farther endwith suitable means 10, for engaging the signal operating mechanism.

The door at its under side has the two downwardly extending projections11 and 12, and the operating bars have the two apertures 13 and 14,adapted to cooperate respectively with said projections.

hen the bars are withdrawn wholly or in part, as illustrated in Fig. 1,with the lower ends of said pro jections resting upon them, the fingers15 of the door will overlap the spaces 3 intervening between the shelvesof the cabinet; and will prevent the removal from the cabinet of any ofthe tablets: hence when the door is in this position, the cabinet issaid to be locked. The bars 8 and 9 are so connected to the signalingmechanism, that when their apertures 13 and 14, are brought intoregistration with the projections 11 and 12, the signals will be set atdanger: or to speak more accurately, they will be permitted to assumethe danger position, towards which they always tend, by reason of thecounterbalance with which they are each invariably provided. \Vhen thebars are inthe position just referred to, with their apertures inregistration with the projections of the door, the door will dropdownwardly by gravity, with its projections received into saidapertures. The fingers 15 of the door will then register with theshelves of the cabinet, leaving the intervening spaces 3, between theshelves, in registration with the cutaway portions of the door, andconsequently all the tablets will then be accessible: hence when thedoor is in this position, the cabinet is said to be unlocked.

To increase the power of the downward projections of the door, to resistan outward pull upon the operating bars, the thickness of the bars ismade less than the vertical travel of the door, and the apertures 9, inthe front of the cabinet, are each provided in the bottom thereof, witha small aperture 9, into which the lower end of the projections of thedoor extends, after having passed downwardly through the apertures 13and 14 in the bars.

When the operating bars have been moved forward till the signal is atdanger, and the cabinet unlocked, it will be noticed that the door, bythe same movement that unlocks the cabinet, locks the signal operatingbars in the danger position; thus securing the signal against casual oraccidental displacement.

The cabinet carries a number of tablet locks located at the rear of theshelves, and in the present instance, divided into two groups of foureach, the right hand group being designated by the numeral 16; and theleft group by the numeral 17. These locks are supported by a suitablenumber of plates 18, in the present instance two being shown, one nearthe top and the other near the bottom of the cabinet (Figs. 2, and 11).These plates have apertures sufliciently large to snugly receive theends of the groups of locks therein as shown. It will be observed thateach of these locks has, at some point within its length, a forwardprojection with an inclined under side. From Fig. 11 it will be seenthat each one 1' these projections, is located immediately opposite oneof the spaces between the shelves of the cabinet, so that when a tabletis properly entered within one of said spaces, the projecting portion ofits base piece will extend underneath the inclined projection of one ofthe tablet locks, and will, slightly elevate the lock, and will supportit in that elevated position as clearly illustrated in. Figs. 8 and 11.Hence when the tablets are all entered in their proper places in thecabinet, the locks are all elevated and supported thereby; and but forthis support the locks would all drop downwardly, till their lower endsrested on the operating bars. It is therefore apparent that wheneverthis sup port is removed from one of the locks by the with drawal of atablet from the cabinet, its lock will dEop downwardly by gravity intoengagement with the forward one 19, of the series of apertures 19, withwhich each bar is provided, since said aperture is always immediatelybeneath the downwardly extending projection 20 of the locks when the baris in position to unlock the cabinet, and thereby render the tabletsaccessible. A tablet cannot be withdrawn from the cabinet as illustratedin Fig. 11, when the operating bar is in the position there shown,unless the door be first removed.

The object of providing a whole series of apertures 19 will be explainedfurther on.

From the foregoing it is manifest that the tablets can only be renderedaccessible by bringing the bar into position to display the dangersignal and locking it in that position and that the removal of one ormore tablets from the cabinet further locks the bar, and that in orderto change the barand through it the signals' the most convenient way isto restore all the tablets to their normal places in the cabinet andlock them there.

In operating two signals, as for instance, an east bound and west boundfrom a single cabinet, it be comes necessary to have one portion of thecabinet for east bound orders and another for west bound; the east boundtablets cooperating with the group of locks controlling the east boundsignal, and the west bound controlling the group cooperating with thewest bound signal. With this arrangement it is necessary that the twokinds of tablets should be easily distinguished, the one from the other;and for this reason I print plainly on one group of tablets the wordEast and on the other the word West. Of course the two kinds of tabletscould be made to differ from each other in size, shape, color, printedform thereupon etc; but desiring to meet the problem in its mostdifficult form, I have, in the present instance, provided for the use ofblanks alike in all these respects. It the tablets were not readilydistinguishable, an operator called upon to receive an order, mightwithdraw and use the wrong tablet, which would look the wrong signal,and leave the other still free, the evil results of which are readilyperceived. Hence it is of the utmost importance that every precaution betaken to prevent any confusion of the tablets, and therefore in thepresent applicationl have provided means which prevents any mixing orconfusion of the tablets, and compels that when placed in the cabinet,they be placed in their proper compartments, and that if a single one ofthe three kinds be entered in the wrong place, the cabinet will therebybe locked throughout, with both the signals at danger and the cabinetrendered inoperative. These results are accomplished by the meansillustrated in Figs. 510.

From Figs. 4, 8, and 9 it will be seen that the outer one of each groupof tablet locks, has its inclined projection near its lower end, inposition to be engaged by the tablet carried by the lower shell, andthat both groups of locks are suitably cut away to permit this; but inregard to the other three tablets of each group it will be noticed thatthe inner three of the right hand group, have their inclined projectionsopposite the three upper shelves, with that portion of the said group oflocks opposite these shelves suitably cut away, to permit the tablets toenter underneath the projections; while the corresponding portion of theleft hand group is not cut away. Again it will be noticed that the threeinner members of the left hand group of locks, have their inclinedprojections in a position to be opposite the fourth, fifth and sixthshelves of the cabinet, and that the lower part of this group of tabletsis also suitably cut away to permit the tablets carried by these shelvesto enter underneath the projections, but that the portion of the righthand group of locks opposite these three shelves (fourth, fifth andsixth) is not cut away.

The tablet illustrated in Figs. 5 and 8, has the left side of itsprojecting base piece cut away, which permits the remaining portion ofsaid base piece to enter underneath the inclined projections of theright hand group of locks; said projections being opposite the uppershelves. If however, through mistake, it were attempted to enter thisform of tablet in the fourth, fifth or sixth shelves of the cabinet, theuncutaway projection of the base piece would abut against the uncutawayportion of the right hand group of tablet locks, and would prevent thetablet from further entering any one of said shelves, as clearlyillustrated in Figs. 9 and 11. It will be readily seen that the form oftablet illustrated in Fig. 6, having the right hand side of itsprojecting base piece cut away, will cooperate with the locks havingtheir projections opposite the fourth, fifth and sixth shelves of thecabinet, that is, the three inner locks of the left hand group, but thatit will not cooperate with the locks operated from the three uppershelves, as its projecting portion would abut against the uncutawayportion of the left group of tablet locks.

The form of tablet illustrated in Fig. 7, when entered in the lowershelf of the cabinet as illustrated in Fig. 10, will engage the outermember of each group of looks, but cannot be entered in any other shelfof the cabinet; for if it be attempted to enter it in any one of thethree upper shelves, its projecting base piece willabut against theuncutaway portion of the left group of locks: and if it be attempted toenter it in the fourth, fifth or sixth shelves, its base piece Will abutagainst the uncutaway portion of the right hand group of locks. If it beattempted to enter one of the tablets from either of the uppercompartments of the cabinet, in the lower shelfdesigned only for thisform of tablet-it cannot be done, for the lower shelf has the stop 21,centrally located in front of the tablet locks, and since the centralportion of the projecting base piece of the tablets used in thesecompartments is not cut away, this stop will constitute an effectual barto their entrance into this shelf. The form of tablet designed for thisshelf is permitted to pass this stop, by having the central portion. ofits projecting base piece cut away, as clearly illustrated.

The right and left groups of locks cooperate respectively, with theright and left operating bars; and as in the present instance the righthand bar is supposed to control the east bound signal and the left handbar the 'west bound, and the inner three of the right hand group oflocks, are operated by the tablets carried in the three top shelves ofthe cabinet; and the inner three of the left group of locks arecontrolled by the tablets carried in the fourth, fifth and sixthshelves; and the outer member of each group of locks is controlled bythe tablet carried in the bottom shelf, therefore I have called thetablets designed for the first three shelves, the east bound tablets;those for the fourth, fifth and sixth shelves, the west bound tablets;and that carried by the seventh shelf, the double tablet. The locksoperated by these tablets may be designated in the same way that thetablets are; i. e. they may be called east bound locks, west boundlocks, and double locks.

When there is an attempt to enter a tablet in the wrong compartment, theportion of the tablet projecting in front of the cabinet will preventthe door from being elevated out of engagement with the operating bars,and hence both signals will be locked at danger by the door of thecabinet, whenever such an attempt is made.

In Figs. 11, 12, and 13 I have illustrated means, independent of thetablets for controlling the tablet locks. It frequently happens that anorder for a train, is given long before the time for the arrival of saidtrain, and in the mean time other trains going in the same direction,and for which there are no orders, arrive and should be given the clearsignal. Now with the apparatus as thus far explained, the signal will belocked when these latter trains arrive, and can only be unlocked byreturning the tablet to the cabinet; but as the tablet contains upon itan undelivered train order, it must not be returned to the cabinet, lestit be forgotten and left there, and a collision ensue. Hence the problemarises as to how to give a clear signal to a train for which there areno orders, while there are orders on hand for'another train not yetarrived. This result is accomplished by the following means. In the rearpart of the two groups of tablet looks, I provide the notches 22 and onthe inside of the back of the cabinet, I attach in any suitable way, thetwo small bars 23one for each group of locks. Each of these bars isprovided with an inwardly extending portion 24, so located withreference to its group of tablet locks, that it extends into the notches22 of the same, and is normally barely out of engagement with the upperside of said notch,.when the tablets are withdrawn from the cabinet andthe locks in their downward position with the portion 20 received intoone of the apertures 19 of the operating bar.

In the back of the cabinet is a keyhole permitting the insertion of asuitable key, immediately underneath the projection 24, and by a properturn of this key, the said projection 24 will be elevated, and willcarry up with it, out of engagement with the operating bar, whateverlocks of its group that have been caused to drop downwardly by theremoval of one or more tablets from the cabinet. It is manifest thatthis will free the operating bar and permit it to be withdrawn. Howeverthere is one point that must be carefully guarded, and that is that thekey shall not be left in the cabinet in a position to hold a group oflocks elevated out of engagement with its operating bar; for though thecounterbalance of the signal would again bring it to danger it would notbe locked in that position through its operating bar, and the purpose ofthe invention would thereby be defeated. Hence to effectually guardagainst danger at this point I have provided means compelling theremoval of the key from the cabinet, every time the signal is set clearso that the lock shall be permitted to unfailingly drop again intoengagement with the operating baruvhenever the counterbalance of thesignal brings it back into its normal position. This is effected bymeans of an angle 25, one of which is carried by each operating bar, andis so located thereupon that it must come up against the rear side ofthe cabinet before the signal is fully at safety; and since the key isin the path of the angle as it moves inwardly, this compels the removalof the key before the operation of clearing the signal is completed, asa means of finishing the operation.

Fig. 13 illustrates means for operating the mechanism shown in Fig. 12,without a key. Instead of the key I provide a small rod 26, rigidlyattached to the bar 23, and extending outwardly through a suitable slot27. By simply elevating therod 26, the same result will be accomplishedas is accomplished in the other case by a proper turn of the key. But ifthe rod 26 be secured in its elevated position, the same evil resultwill follow that makes it necessary to compel the removal of the keyfrom the cabinet in the construction above. Hence it becomes necessaryin this case to provide means compelling that the rod 26 be lowered toits normal position before the operation of clearing the signal can becompleted. To this end I have provided the angle 25 with the aperture 28so located as to register with the rod 26 only when the said rod is inits downward position, the result of which is apparent without furtherspecification. The key and the rod may both be made quite long ifdesired, so that the freeing of the tablet locks may take place at anearly stage in the operation of clearing the signal.

One more contingency needs to be provided for. It might sometimes happenthat an operator after having given a clear signal would fail tocarefully set his signal back to danger, when he had undelivered trainorders on hand; and due to sleet, snow or other cause, the counterbalance of the signal might not bring it entirely back to danger; or thesignal might be slightly out of order: and if under these circumstancesan operator were to forget that he had undelivered train orders on hand,and were to seize the operating bar upon the approach of a train, therewould be nothing to prevent him from pulling the signal to clear. Toprevent this I have provided the series of ratchet notches 19, in eachof the operating bars, so that when the signal has moved only half wayto danger, these notches will begin to engage the downwardly extendingprojection 20 of the tablet locks, and thereby lock the operating bar sothat it cannot be carelessly or thoughtlessly withdrawn. Of course thisoperation only takes place when one or more tablets have been removedfrom the cabinet, as the presence of the tablets in the cabinet holdsthe locks entirely out of engagement with the operating bar. The seriesof ratchet notches 19 may extend throughout more than one half of thetravel of the operating bars, but it is thought that that much willalways be sufficient, as the signal would not be used if it did not goautomatically at least half way to danger. Hence it will be seen thatthe locking mechanism is rendered automatic in its action by the removalof one or more tablets from the cabinet; so that while there areundelivered train orders on hand, the signal even if left to itself,will assume the danger position, and be automatically locked in thatposition. Of course the last contingency above referred to is soimprobable with my device as to scarcely merit attention, since thefailure of either signal to return to its proper position, would leaveits operating bar projecting in front of the cabinet, so that ordinarilythe operator could scarcely fail to notice it and thereby be Warned ofthe condition of the signal.

In the use of my invention, I recommend the following points as worthyof consideration: Let each of the three different kinds of tablets used,be printed on paper of a different color, in addition to having itsproper name plainly printed upon it; as for instance, let the tabletsfor east bound orders be made of white paper, and let the word East beplainly printed upon the tablet or upon each blank thereof. Let thetablet for west bound orders be made of blue paper with .the word Westplainly printed upon each blank thereof; and let the tablet for doubleorders, be made of pink paper with the word Double on each blank. Itwould perhaps be well to make this latter tablet a different size orshape, to render it still different from the others. In selecting colorsfor these tablets, always avoid these colors not readily distinguishablefrom each other under all conditions. For instance, if white be selectedfor the color of the east bound orders, avoid the use of yellow for westbound tablets, as yellow is not easily distinguished from white byartificial light, Next, let the proper oflicial issue an order that notrain order shall be accepted or honored by conductors or enginemen,unless it be upon a blank of the prescribed form and color, required fortrains running in that direction. Let the same principle be also appliedto double orders as occasion may require.

At present train despatchers procced somewhat as follows: Let us supposethat a despatcher desires an operator to take five copies of an orderabout to be given.

' After having called the operator to his telegraph instrument he wouldsay cy. 5 or cpy. 5, which would indicate to the operator that he was totake five copies-- one original and four carbonsof the order about to begiven. Of course the operator would not know till the order was receivedwhether is was for an east bound or a west bound train. In the use of myinvention however, as herein set forth, it is necessary that theoperator know at once, what kind of an order is to be received, whetheran east bound, a west bound, or a double order, so that he can withdrawthe proper tablet upon which to receive it. In order that this mayalways be immediately known, I suggest that in giving orders thedespatcher substitute for cy or cpy, the letters E, W, or D, accordingas the order about to be given is to be received on an east bound, awestbound, or a double order tablet. Thus E 5 would mean Take five copies ofan east bound order and the operator would instantly know to take atablet from the compartment of the cabinet, designed to house the eastbound tablets: and he would have five distinct ways to know that he hadthe proper tablet and no other. First, the despatcher has told him totake an east bound tablet. This appeals to his ear. Secondly, the tablethas East printed upon it. This appeals to his eye.

Thirdly, it is made of white paper, and this appeals again to his eye.Fourthly, he would from force of habit always reach to the same place inthe cabinet for any given kind of orders. Finally, he would know fromthe contents of the order, whether or not the despatcher had made amistake in naming the kind of tablet the order was to be received upon.If the right tablet be withdrawn from the cabinet, the proper signalwill be locked at danger without the necessity of so much as everthinking about the signal at all.

Having thus fully set forth the principles of my invention, and shownmeans of applying the same to practice, I yet do not wish to limitmyself to the exact showing made; but desire protection on all thatcomes n I 0 a clearly w1th1n the spirlt and scope of my invention.

What I claim as new and desire to secure by Letters Patent is:

1. In interlocking devices for train order signals, a cabinet havingcompartments; a definite kind of tablets in each compartment; and meanscoiiperatlng with said tablets to permit them to be entered only intheir proper compartments in said cabinet.

2. In interlocking devices for train order signals, a cabinet carrying aseries of tablets; and having stops, whereby said tablets are preventedfrom entering any but the proper compartments of said cabinet.

3. In interlocking devices for train order signals, a cabinet havingcompartments each carrying tablets for trains running in a givendirection or directions; and means de' signed to prevent theindiscriminate entering of said tablets within said compartments =1. Ininterlocking devices for train order signals, a cabinet having acompartment for east bound order blanks and another for west bound orderblanks; said blanks being made different from each other for purposes ofdiscrimination; each of said compartments being designed to receive andhouse only the form or tablet designed therefor. I

In interlocking devices for train order signals, a cabi' not havingseparate compartments designed for east bound orders, west bound orders,and "double orders respectively; each compartment being formed toreceive and house only the kind of orders intended therefor.

G. In interlocking devices for train order signals, a cabinet having acompartment for east bound train order tablets and another for westbound order tablets; each of said. kinds of tablets differing from theother, and each of said compartments designed to receive only thespecial kind of tablets intended therefor.

7. In interlocking devices for train order signals, a cabinet having acompartment for east bound train order blanks, another for west boundorder blanks, and another for double order blanks; each of said kinds ofblanks being dilferent from the other, and each of said compartmentsdesigned to receive only the special kind of blanks intended therefor.

8. In interlocking devices for train order signals, a cab.i net havingtrain order tablets normally housed therein; signal actuatingconnections; and interlocking devices co operating with said mechanism,whereby the device is rendered inoperative, with the signals locked atdanger, whenever it is attempted to enter one of the tablets in a wrongcompartment.

1). In interlocking devices for train order signals, a cabinet carryingtablets for east bound orders, west bound orders, and double orders; andsignal actuating mechanism in collperative relation to said tablets,whereby each east bound tablet controls the east bound signal; each westbound tablet controls the westbound signal; and the double order tabletcontrols both signals.

10. In interlocking devices for train order signals, a cabinet carryingeast bound orders, west bound orders, and double orders; and signalactuating mechanism in coiiperative relation to said tablets, wherebythe withdrawal from the cabinet of an east bound order, will lock theeast bound signal at danger; the withdrawal of a west bound tablet willlock the west bound signal at danger; and the withdrawal of a doubleorder tablet, will lock both signals at danger.

11. In interlocking devices for train order signals, a cabinet having aseries of tablets normally housed there in; signal actuatingconnections, and a series of locks in operative relation thereto,controlled by the tablets; and means independent of the tablets forunlocking the signal connections.

12. In interlocking devices for train order signals, a cabinet having aseries of tablets normally housed therein; signal actuating connections,and a series of tablet locks in cooperative relation thereto, thesignaling mechanism unlocked and locked by the insertion or withdrawalre' spectively, of a tablet; and independent means for unlocking saidsignaling mechanism while a tablet is withdrawn from the cabinet.

13. In interlocking devices for train order signals, a cabinet having aseries of tablets normally housed therein; signal actuating mechanism;tablet locks for locking and unlocking the same; means independent ofthe tablets for unlocking the signaling mechanism to give a clearsignal; and means for compelling the release of the tablet locks fromthe control of said independent means, and the bringing of them againinto operative relation to the signaling mechanism, every time. thesignal is cleared by said independent means.

14. In interlocking devices for train order signals, a cabinet having aseries of tablets normally housed therein; signal actuating connections;a series of tablet locks in operative relation thereto, locked andunlocked by the tablets, and converted into gravity locks by the removalof their tablets from the cabinet; means independent of the tablets forunlocking the signaling mechanism; and further means carried by saidsignaling mechanism and designed to be engaged by said locks as thesignal returns to danger after having been set to clear by saidindependent mechanism, whereby a signal having been set to clear andonly partially returned to danger will nevertheless be locked inwhatever position it assumes, if there be undelivered train orders onhand.

15. In interlocking devices for train order signals, a cabinet for trainorder blanks; stops within said cabinet; and train order tablets havingcut-away portions to prevent them from contacting with said steps.

16. I11 interlocking devices for train 'order signals, the combinationwith signals for trains running in opposite directions, of a cabinethaving blank train order tablets for trains running in each of saiddirections; actuating connections between each of the signals and thecabinet; said connections between either signal and the cabinet beingcontrolled by the tablets intended for trains controlled by that signal.I

17. A cabinet having separate compartments designed to respectivelyreceive tablets of train order blanks for trains running in differentdirections, each of said compartments being formed to receive and houseonly the kind of tablets for which it is designed.

18. A cabinet having separate compartments designed to respectivelyreceive tablets of train order blanks for trains running in diiferentdirections; and locks for each compartment, to lock and unlock thesignal controlling trains running in the direction for which the tabletsto be carried in that compartment are designed; the locks of eachcompartment being adapted to be controlled only by the tablets designedfor that compartment.

19. A cabinet having separate compartments for containing respectively,tablets of train order blanks 'for trains running in diiferentdirections; and means connected with each compartment of the cabinet forlocking the signal controlling the trains to which the tablets to becarried in that compartment relate; said means, in each compartment,being adapted to be operated only by the individual tablets designed forthat compartment.

20. In interlocking devices for train order signals, a cabinet havingseparate compartments designed for east bound orders, West bound orders,and double orders, respectively; tablets of train order blanks for eachof said compartments, said tablets being formed to fit only thecompartments for which they are respectively designed.

21. In interlocking devices for train order signals, the combinationwith signal actuating mechanism, of an auto matic lock therefor; meansfor moving the lock into inoperative position, to permit a partialoperation of said mechanism; and additional means requiring therestoration of the lock to its normal automatic condition, in order topermit the completion of said operation.

22. The combination with signal actuating mechanism of a lock therefor;cooperating means between said lock and said actuating mechanism fornecessitating the movement of the lock to different positions to permita complete operation of said actuating mechanism; and means forimparting to the lock the necessary movements.

23. The combination with signal actuating mechanism of an automatic locktherefor cooperating means between said lock and said actuatingmechanism, for necessitating the movement of the lock to differentpositions to permit a complete operation of said actuating mechanism;means for imparting to the lock the necessary movements with the finalmovement of the lock leaving it in position to automatically engage saidactuating mechanism when the same is moved to locking position.

24. The combination with signal actuating mechanism, of a lock therefor;a tablet cooperating with said lock and adapted when in one position torender the lock inoperative, and in another position to render itautomatic in its action; independent means for controlling the lock whenin its automatic condition, to permit a partial operation of theactuating mechanism; and additional means compelling the restoration ofthe lock to its automatic condi tion during the latter part of eachoperation of the actuating mechanism, in order to complete saidoperation.

25. The combination with signal actuating mechanism, of a lock therefor;means for moving the lock into inoperative position to permit theoperation of said mechanism, said lock when in inoperative positionhaving a part connected therewith disposed in the path of a part of thesignal actuating mechanism, and adapted to arrest the movement of saidmechanism before a complete operation of the same has been effectedthereby, said lock being movable to a diiferent position to permit thecompletion of the operation of said actuating mechanism.

26. The combination with signal operating mechanism, and a cooperatingautomatic lock, of means for compelling the bringing of the lock andsaid signal operating mechanism, into normal operative relation to eachother during the movement of said mechanism necessary to set the signalclear.

27. The combination with a tablet and a-support therefor, ofsignal-operating mechanlsmz' a signal lock coop crating with saidmechanism and said tablet and rendered automatic by the removal of thetablet from its support: and independent means for operating said lockwhen said tablet is removed from its normal position.

2%. The combination with a tablet support and a tablet: of signaloperating mechanism: a lock controlled by the tablet and cooperatingwith said mechanism to lock the signal at danger and adapted to berendered automatic by the removal of the tablet from its normalposition: independent means for operating the lock to permit changingthe signal to safety while the tablet is thus removed: and additionalmeans compelling the restoration of said lock and said operatingmechanism into normal operative relation to each other before thecompletion of the movement of said mechanism necessary to set the signalclear 29. The combination with a tablet support and a tablet: of signaloperating mechanism: a lock controlled by the tablet and cooperatingwith said mechanism and adapted to be rendered automatic by the removalof the tablet from its normal position: independent means for operatingthe lock: and a stop preventing the complete movement of said mechanismnecessary to clear the signal, when said lock is held in inoperativeposition by said independent means.

30. In interlocking devices for train order signals, a cabinet having acompartment for train order tablets for trains running in a givendirection and another compartment for tablets for trains running in adilferent direction; and operative connections between each compartmentand the signal controlling the trains to which the tablets in thatcompartment relate.

31. In interlocking devices for train order signals, a cabinet adaptedto carry train order tablets for trains running in different directions;said cabinet having actuating connections adapted to operate the signalscontrolling trains running in said directions, the actuating connectionsbetween either signal and the cabinet being controlled by the tabletsintended for trains controlled by that signal.

32. The combination with signal-operating mechanism of a lock adapted toautomatically lock the signal at danger means for manually operating thelock to release the signal when it is desired to set the same at safety;and means compelling the freeing of the lock from manual control and therestoration thereof to its automatic condition as a prerequisite to thecomplete operation of said mechanism necessary to set the signal atsafety The combination with a lock adapted to automatically lock asignal at danger, of independent means for releasing the signal when itis desired to set the same at safety; and means compelling therestoration of the signal and lock to their normal relation to eachother in order to complete the operation of changing the signal fromdanger to safety.

34. A cabinet having separate compartments for containing respectively,tablets of train order blanks for trains running in differentdirections; and means connected with each compartment of the cabinet forlocking the signal controlling the trains to which the tablets to becarried in. that compartment relate; the locks controlled from eachcompartment of the cabinet being independent of those controlled fromany other compartment thereof.

35. In a device of the character described, a lock for each signal to becontrolled, each lock having a cutaway and an uncut-away portion, thecutaway portion of each lock being opposite the uncutaway portion of theother.

36. In a device of the characted described, a lock for each signal to becontrolled, each lock having a cutaway and an uncutaway portion, thecutaway portion of each lock being opposite the uncutaway portion of theother; and each lock also having a second cutaway portion, the twolatter cutaway portions being opposite each other.

37. In locking devices for signals on double track roads, a lock foreach signal to be controlled, each lock having a cutaway and anuncutaway portion, the cutaway portion of each lock being opposite theuncutaway portion of the other and provided with means adapted to beengaged for operating the lock.

38. In locking devices for signals on double track roads, locks for eachsignal to be controlled, each lock having a cutaway and an uncutawayportion, the cutaway portion of the locks for each signal being oppositethe uncutaway portion of the locks for the other signal; and each lockalso having a second cutaway portion, the latter cutaway portions beingopposite each other, one of the cutawayportions of each lock beingprovided with means adapted to be engaged for operating the lock.

39. In locking devices for signals on double track roads, locks for eachsignal to be controlled, each lock having a cutaway and an uncutawayportion, the cutaway portion of the locks for each signal being oppositethe uncutaway portion of the locks for the other signal, and each lockalso having a second cutaway portion, the latter cutaway portions beingopposite each other, each lock being provided at one of its cutawayportions with means adapted to be engaged for operating the lock, thelock operating means in the latter cutaway portions being opposite eachother 40. In signal controlling mechanism, a cabinet having compartmentsdesigned to receive tablets of train order blanks for trains controlledby different signals; a lock for each signal, said lock being adapted tobe engaged and operated by a tablet relating to that signal, each lockex tending across the different compartments of the cabinet and beingcutaway where it is adapted to be engaged and operated by a tablet, anduncutaway where it is not intended to be thus engaged and operated.

41. In interlocking devices for signals, a cabinet having compartmentsdesigned to receive tablets of train order blanks for trains running indifferent directions and controlled by ditferent signals; a group oflocks for each signal to be controlled, the group relating to any givensignal. being adapted to be engaged and operated by the tablets 10relating to that signal, each group of locks extending across thedifferent compartments of the cabinet and being cutaway where tney areadapted to be engaged and operated.

In testimony whereof I affix my signature, in presence of two witnesses.

EDWIN E. OVERH 0LT.

Witnesses:

W. B. MATTHEWS, M. V. Ma'r'ri-mws.

